Electric transmission of intelligence.



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ELECTRI TRANSMISSION (DF INTELLIGENCE.

Specification of Letters Patent.

Patented Oct. 31, 1905.

Application led Tulle 24, 1904. Serial No. 213,989.

I all whom, t may concern:

Be it known that I, IsIDoR Krrsrm, of the city and county of Philadelphia, State 0f Pennsylvania, have invented certain new and useful Improvements in the Electric Transmission of Intelligence, of which the following is a specification.

My invention relates to an improvement in electric transmission, and has more special reference to the improvement of telephonie circuits. In such circuits wherein the stations include an induction-coil the primary of which is connected t0 the microphonic transmitter and battery and the secondary of which is connected to the line of transmission it is a known fact that in long-distance transmission the waves constituting the speech to be transmitted are retarded and distorted if such line is of any considerable length. This .retardation and distortion is iny some cases due t0 the capacity and in some cases to the resistance and inductance of the line. In my experiments to overcome these disadvantages I have employed conductors or coils consisting of closely-twisted pairs of wires, the twist 0f these wires less than one-half inch apart. These cinductive devices, asIcall them, are inserted in series in the line in a manner so that one terminal 0f one wire 0f said pair of twisted wires is connected to one terminal of the line andthe opposite terminal of the other wire of said pair connected to the other terminal of the line, one terminal of each wire of said pair remaining free. I have found that with the introduction 0f these devices the speech became clearer and lost a great deal of what is technically called the metallic sound. I employed, besides others, a device consisting of a board about eighteen inches long and twelve inches wide as a support, around which was wound in one layer about seven hundred and eighty feet of twisted wire, substantially as is illustrated in the drawings, and on such a line where speech could not commercially be transmitted the transmission became satisfactory after the insertion of such boards.

Referring t0 the drawings, Figure lis a plan View of the device substantially such as was employed by me in some of my experiments. Fig. 2 is a diagrammatic view of a telephonic circuit arranged substantially as one of the circuits employed in some of my experiments..

In Fig. l, A is the device as an entirety, of which A is the board proper and B B' the pair of twisted wires wound around such board. It is obvious that the wires are insulated from each other.

In Fig. 2, C C are two telephonie stations connected together by the line-wire D and D, in which line the devices A A A A are inserted in series.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In telephonie transmission, an all-metallic line, a series 0f inductivedevices inserted at different points in said line-wire and adapted t0 increase the efficiency thereof, each 0f said inductive devices consisting of a pair of twisted wires, one terminal of one wire of said pair connected to one terminal of the line and the opposite terminal of the second wire 0f said pair connected to the other terminal of` said line, one terminal of each wire of said pair remaining free.

2. In combination with an all-metallic telephonic circuit of transmission, a series of devices inserted at dilferent points in said line and adapted to increase the efiicieney of said line, each of said devices consisting 0f asupport, a pair 0f twisted wires around said support, one terminal of each of said twisted wires connected to the line and the other terminal of each of said twisted wires remaining free.

3. In combination with an all-metallic telephonie circuit, a series 0f devices inserted each at different points in said line and adapted to increase the efliciency of said line, each of said devices consisting of a support, a pair 0f twisted wires wound around said support in a manner so that of the two ends 0f the pair, one wire at each end is connected to the line and one wire at each end remains free.

4L. A device adapted t0 increase the efliciency of an all-metallic circuit, said device consisting of a support and a pair of twisted wires wound around said support, each twist of said wires not longer than one inch, one end of each 0f said wires provided with means to connect the same to a cu rrent-carrying circuit and one end 0f each of said wires remaining free.y

In testimony whereof I hereby sign my name, in the presence of two subscribing witnesses, this 21st day 0f June, A. D. 1904.

ISIDOR KITSEE.

Witnesses:

EDITH STILLEY, I-I. D. YETTER.

IOO 

